C# 撒列实现关键字过滤的实例

class Program
    {
        static void Main(string[] args)
        {
            string keys = "云风博客|并发问题|最烂的方法|内存|集合|数据库|性能";

            using (new OperationTimer("keyWords:"))
            {
                WordSearch ws = new WordSearch(keys);
                string str = "看云风博客关于解决12306并发问题的启发：我现在做骏卡接口，可能出现并发问题，就是一个订单可能向我们的接口发送多个请求，而我现在做的方法是去数据库中对应的表验证，看订单是否存在，如果存在就提示一下，如果不存在按流程走，但是这个样每来一个订单我都需要去数据库查，如果我在内存中维护一个订单集合，这样就能很快解决判断订单是否存在的问题，惯性思维太严重了，什么都去数据库查，这样的性能是最差的，其实很多问题在内存中就可以搞定的，最近还有一个特别感受，不要做井底之蛙，多看牛人的东西收获真的比自己埋头写代码进步快很多，其实很多时候我写的程序性能差，效率低都是因为方法的原因，没有找到好的方法，没有灵光一闪的感觉，用了最烂的方法解决问题";
                ConsoleColor color = Console.ForegroundColor;
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("原文：");
                Console.ForegroundColor = color;
                Console.WriteLine(str);
                Console.WriteLine();
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("过滤后：");
                Console.ForegroundColor = color;
                Console.WriteLine(ws.Filter(str));
            }
            Console.Read();
        }

    }

using System;
using System.Diagnostics;

namespace WordFilter
{
    /// <summary>
    /// 测试代码运行时间帮组类
    /// </summary>
    public class OperationTimer : IDisposable
    {
        private string Text;
        private Int32 collectCount;
        private Stopwatch stopWatch;

        public OperationTimer(string txt)
        {
            PerpareForOperation();
            this.Text = txt;
            collectCount = GC.CollectionCount(0);
            stopWatch = new Stopwatch();
            stopWatch.Start();
        }

        public void Dispose()
        {
            stopWatch.Stop();
            Console.WriteLine("{0} Milliseconds (GCs={1}) {2}", stopWatch.ElapsedMilliseconds, GC.CollectionCount(0) - collectCount, Text);
        }

        private static void PerpareForOperation()
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
        }
    }
}

      public Dictionary<char, IList<char>> HandleKeyWords(IEnumerable<string> text, int size)
        {
            Dictionary<char, IList<char>> dicList = new Dictionary<char, IList<char>>(size);//预分配非常关键
            int len, i;
            foreach (string s in text)
            {
                if (s == string.Empty)
                {
                    continue;
                }
                len = s.Length - 1;
                for (i = 0; i < len; i++)
                {
                    if (dicList.ContainsKey(s[i]))
                    {
                        if (dicList[s[i]] != null && !dicList[s[i]].Contains(s[i + 1]))
                        {
                            dicList[s[i]].Add(s[i + 1]);
                        }
                    }
                    else
                    {
                        dicList.Add(s[i], new List<char>(2) { s[i + 1] });
                    }
                }
                if (!dicList.ContainsKey(s[len]))
                {
                    dicList.Add(s[len], null);
                }
            }

            return dicList;
        }